More than 14,000 people have run through the streets of Auckland this morning.
Thousands of athletes and amateurs have signed up for the Auckland Marathon's five races, including hundreds of children for a 2.2km kids' marathon.
It's the festival's 32nd iteration, with organisers saying they are on track to meet the $600,000 fundraising goal.
The event's organiser, Ironman Group regional director Amy MacCormack, said they were well on track to meeting that goal.
She says it's incredible to see so many runners working together for a good cause.
Ms MacCormack says runners of all ages are participating, some as young as five and others in their eighties.
"It's pretty incredible to see all these runners running for a cause, to get behind charity fund-raising," she said.
By Wednesday the event had already raised $450,000.
That money will be donated to 10 charities, including the Auckland City Mission, Cancer Society, SPCA and Starship Foundation.
MacCormack said the event would start early in the morning.
"Our first event is kicking off at 6am in Devonport," she said.
"[I'm] really excited to see thousands of athletes hit the bridge, onto the streets through the CBD and to the finish line at Victoria Park."
She said the half marathon would start next, at 6.50am.
Other events included the 11km Traverse, the 5km run and one aimed at children aged five to 12.
"I love the kids' race, seeing so many excited children hit the streets for a 2.2km run. It's pretty incredible," MacCormack said.
She said 62 percent of the runners were first-timers for the event.
All the races will end at Victoria Park, where screens broadcasting the Rugby World Cup final would greet runners at the finish line.
"We're going to have a large screen broadcasting the live footage of the Rugby World Cup," she said.
Runners who missed the rugby would have a chance to watch replays, MacCormack said.
"We'll make sure everyone coming into the park can enjoy the rugby, and hopefully an All Blacks win."